North American Fruit Explorers mailing list at ibiblio

["Lon J. Rombough" <lonrom@hevanet.com>]

Title: Re: [NAFEX] Cloning

    In many plants, especially trees, there is a juvenile and an adult phase.  Often, the juvenile phase has differences in appearance from the adult phase, AND the juvenile phase roots much more readily. 
    When a new pear variety was released here in Oregon some years ago, some of the propagated trees were producing thorns, which is a character of the juvenile phase.  Nurserymen were advised to propagate from the non-thorny parts as much as possible to get trees that were all "adult" and no longer thorny.  
    Second item.  When suckers come from the roots of most fruit trees, they are in juvenile phase.  You can have an adult, own rooted tree, but if you take root cuttings, the trees that grow from the roots will usually have to go through their own juvenile phase before they become adults.  Apparently buds forced from root tissue start out in a juvenile phase.
    If the old cultivars were being grown from rooted cuttings, there was plenty of opportunity for them to push sprouts from roots, which would be juvenile.  On the other hand, if you propagate a tree by grafting, you are constantly using the adult wood, so that you get to a point where a tree is ALL adult wood, which is much harder to root, but will still graft easily.
    I suspect that if you were to layer a tree of one of those old varieties to get it on it's own roots, and then forced root sprouts, THOSE sprouts would root from cuttings more readily because THEY would be in juvenile phase again.
> -Lon Rombough
Grapes, writing, consulting, my book, The Grape Grower, at http://www.bunchgrapes.com


>
Cider apples from England still exist as clonal genotypes that were propogated during the 1700's by rooting that today can NO LONGER be rooted. Unless the English of that era possessed rooting techniques better than we do now, the conclusion would be drawn that some cider apple cultivars have changed in three centuries.